[AC-1923] Add endpoint to create client organization (#3977)

* Add new endpoint for creating client organizations in consolidated billing

* Create empty org and then assign seats for code re-use

* Fixes made from debugging client side

* few more small fixes

* Vincent's feedback

src/Api/Utilities/EnumMatchesAttribute.cs

@@ -0,0 +1,26 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace Bit.Api.Utilities;
+
+public class EnumMatchesAttribute<T>(params T[] accepted) : ValidationAttribute
+    where T : Enum
+{
+    public override bool IsValid(object value)
+    {
+        if (value == null || accepted == null || accepted.Length == 0)
+        {
+            return false;
+        }
+
+        var success = Enum.TryParse(typeof(T), value.ToString(), out var result);
+
+        if (!success)
+        {
+            return false;
+        }
+
+        var typed = (T)result;
+
+        return accepted.Contains(typed);
+    }
+}